Grinding-wheel-balancing device



GRINDING WHEEL BALANCING DEVICE. APPLlCATiON man APR. I2, 1920.

5 3 1 I Patented Jan. 3,

INVENTOR WIT-"5&6 Es 6/2 02/05 hf 11 017 1 W 1 A'TT'O EY gTATEEi earner@Fhlfiil.

CHARLES H. NORTON, 0F WORCESTER, MASSACHUSETTS, ASSIGNOR TO NORTOIVCOMPANY, OF WORCESTER, MASSACHUSETTS, A. CORPORATION OF MASSA- CHUSETTS.

GRINDING-WHEEL-BALANCING- DEVICE.

Specification of Letters Eatent.

Patented Jan. 3, 1922.

Application filed. April 12, 1920. Serial No. 373,342.

T 0 all whom it may concern:

Be it known that I, CHARLES H. NORTON, a citizen of the United States ofAmerica, residing at Worcester, in the county of Worcester and State ofMassachusetts, have invented certain new and useful Improvements inGrinding-Vfheel-Balancing Devices, of which the following is a full,clear, and exact specification.

My invention relates to balancing devices and more particularly to anabrasive grind ing wheel having adjustable means associated therewithfor balancing the wheel either initially or after the center of gravityhas changed. The device forming the subject of my invention constitutesa modification of the balancing device shown and described in the patentto Thure Larsson No. 1,352,005, dated September 7, 1920, and the mainobjects of my invention are to provide a construction which is simplerin design, more easily and more cheaply manufactured, more readilyassembled and more quickly adjusted than the device shown and describedin the said application.

Further objects will be apparent from the following disclosure as setforth in the accompanying specification and the claims appended thereto.

In the drawings, in which like reference numerals indicate like parts:

Fig. 1 is a side elevation of a grinding wheel showing my inventionapplied thereto;

Fig. 2 is a cross section on the line 22 of Fig. 1;

Fig. 3 is a perspective view of the balancin member.

11 the practice of my invention, I employ an internal peripheral surfaceof a grinding wheel to support a substantially U-shaped balancing memberhaving free ends, and move such member to any desired angular positionand cause these ends to engage the wheel and hold the central portionimmovably against the inner surface. This U- shaped member may comprisea length of resilient material, preferably steel wire, which itselfforms the balancing weight, but in my preferred form has attachedthereto a balancing weight of some heavy metal, such as lead.

Referring to the drawings, which show one specific embodiment of myinvention, I have there illustrated an abrasive grinding wheel 1 havinga centrally disposed aperture 2 therein for fastening the wheel to aspindle and, in the form being described, annular countersunk portionsor grooves 3 around the spindle aperture on each disc face l of thewheel. These annular grooves are normally provided in order that theflanges 0, which clamp the wheel betweenthis space for the purpose ofbalancing the whee in its preferred form, the balancing device maycomprise a substantially U-shaped length of resilient wire, the ends 7of which are straight and the intermediate portion 8 is substantiallyshaped on the arc of a circle. When the device is not in place on thewheel its ends are separated by a distance greater than the diameter ofthe inner periphery of the countersunk groove 3 of the wheel, or asillustrated this are 8 has a greater radius than the radius of thecountersunk portion of the wheel, for a purpose to be pointed out lateron. This wire embodies in its construc tion a weight 10 made, forexample, of leador other suitable material and preferably cast onto thewire. The wire is preferably formed with a sharp bend 9 at this point tohold the lead in place. The ends of the wire are formed with relativelysharp edges 11 which dig into the abrasive wheel when the device isapplied to the wheel and serve to prevent angular displacement andfrictionally and resiliently hold the device in place. As shown in thedrawings, this wire is made longer than half the periphery of thesurface which it is to engage so that its ends will di into the wheelbeyond a diametrical line which is perpendicular to a radius drawn fromthe middle portion of the wire. This insures an adequate frictionalengagement with the wheel. To secure a perfect running balance of thewheel it will be necessary to employ two of these devices, one on eachside of the wheel.

In order to apply the device to an unbalanced grinding wheel theintermediate portion of the wire which carries the weight is placedagainst the inner peripheral surface formed by the grooves 3 and theends of the wire are first flexed inwardly, that is, towards the wheelaxis, and then moved into the annular recess so that when released theywill bear against said surface. The portion of the wire intermediate theends and the weight are then drawn outwardly, thus causing the ends ofthe wire to drag aelr over the projecting abrasive pa"""icles, lilre apawl and ratchet, and dig firmly into the material of the wheel to holdthe weight securely in place by the clan'iping action thus obtained. vIn order to balance a rinding wheel and to keep it in.balance rtr thewhe l has been worn away, it is therefore merely necessary to mount thewheel on a balancing" stand and insert a balancing device of the hinddescribed of the proper weight and at the proper point to balance theheavy side or the wheel.

By means of this construction it is there fore seen that the weight andthe wire may be fastened in a firm manner to the wheel so that it willnot be removed or displaced under the normal stresses of the grindingoperation. It will al o be seen that the device in this simplified formcan be used with different size wheels and can be fastened to any innerperipheral surface at any desired location thereon as may be providedfor this purpose.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent is:

1. An abrasive wheel balancing device comprising an extended resilientmember which has free ends and a heavy middle portion serving as abalancing weight, said member normally having its ends separated by adistance greater than the diameter of an inner peripheral surface of awheel which it is to engage and when in use having its middle portionengaging such a surface and its ends flexed against the resiliency ofthe material to frictionally engage said surface and hold the device inposition.

2. An abrasive wheel balancing device comprising an extended inemliierwhichhas resilient ends and a lead balancing weight fastened to itsmiddle portion, said member being normally curved with its endsseparated by a distance greater than the diameter of an inner peripheralsurface of a wheel which. it is to engage and being longer than half theperiphery of said surface, and

JilCll in use being bent against the resiliency of the material intosubstantially a U-shape with the 'eight fricticnally engaging-said innersurface and its ends flexed and digging into the surface to hold thedevice in position.

3. In combination, a grinding wheel comprising an unbalanced abrasivebody provided with an inner peripheral surface and a member forbalancing the wheel having a weighted middle portion and resilient endportions, said member when flexed outwardly against said surfaceextending more than half way around the periphery and its ends digginginto the surface to holdthe weighted portion frictionally in engagementtherewith. V

4-. In combination, a grinding wheel having a countersunk portionforming an inner peripheral surface, a wheeldiolding flange of lessdiameter than the diameter of said countersunk portion positionedtherein and 7

